Infant incubator

ABSTRACT

An incubator for premature or weakly infants having a base section which serves as a support for both the infant in the incubator chamber and a protective top section made of a substantially transparent material. The incubator chamber is surrounded by an inner and an outer shell. The temperature and humidity of the air in the incubator chamber is controlled by introducing conditioned air into the incubator chamber and withdrawing it between the inner and outer shells.

The present invention relates to an improved infant incubator.

The purpose of an infant incubator is to secure and improve the chancesof survival of a premature or weakly infant. This is accomplished bykeeping the infant in an environment which is warm, moist and containssufficient oxygen. A premature infant has a low body weight, and thus abody temperature which is close to the ambient temperature. Thepremature infant is therefore very vulnerable, to temperature swings,and consequently major efforts have been made to develop incubatorswhich maintain as constant a temperature as possible.

The incubators dominating today's market comprise a lower sectionhousing equipment for adjusting the temperature and the composition ofthe gas delivered to the premature infant. Placed on this lower sectionis an upper section made of a transparent material, through which thereare provided closable portholes to allow the premature infant to becared for without removing the whole of the upper section. Inside theincubator, the infant lies on a mattress which forms the dividing linebetween the upper and the lower section. The gas in the incubatorcomprising air, possibly with the addition of extra oxygen and moisture,circulates up between the walls of the incubator and the mattress on oneside, and down into a corresponding opening on the opposite side of theincubator. To improve the flow pattern of the gas, an inner wall isoften provided in the upper section of the incubator, causing the gas toflow up and down between the outer shell and the inner wall in the uppersection of the incubator. Means for heating, humidifying and circulatingthe air flow are provided in the lower section of the incubator. Thismeans that a heating element and a fan are located in proximity to thepremature infant. The heating'element and fan may be the source of someelectromagnetic radiation, a radiation which at present is the subjectof intense discussion with respect to whether it has any effects onhealth. In addition, and more importantly, a fan of this kind cannot beentirely noise-free and is thus the source of an acoustic nuisance forthe tiny patient.

Moreover, when a porthole is opened in the upper section, thecirculating air will draw the colder air of the surroundings with itinto the incubator, which may cause the temperature in such an incubatorto fall by about 2° C. when a door is open for more than 10 minutes. Atemperature drop of this kind may at first seem to be insignificant, butis most unfortunate for the extraordinarily vulnerable premature infantwho has little energy to burn and low heat capacity. The doors must beopened from time to time to care for and carry out test procedures onthe premature infant. Moreover, it is desirable that the prematureinfant should not be completely isolated from the surroundings since,just as other infants, the premature infant needs body contact—even ifnothing more than the touch of a friendly hand. The portholes in theincubator may therefore remain open for many periods of more than 10minutes.

The object of the present invention is to provide an infant incubatorwhere the aforementioned problems are obviated.

This is achieved according to the present invention by means of anincubator for a prematurely born or weakly infant comprising a basesection which serves as a support for both the infant placed in theincubator and a protective top section or hood which is made of asubstantially transparent material, wherein the base section housesmeans for causing air to circulate to the chamber enclosed by the basesection and the top section, and means for adjusting the temperature,composition and humidity of the air, and ducts for the supply of air tothe chamber and the outlet of air from the chamber respectively, andwherein the top section consists of an outer shell and an inner shell,which shells rest on the base section and wherein the inner shell isopen at the top, and wherein portholes, preferably equipped with covers,are provided in the top section, wherein the incubator air supply ductsopen into the chamber against and on the inside of the inner shell andthe air outlet ducts run out between the inner and the outer shell.

In the present infant incubator, the air flows in on the inside of theinner shell in contrast to the previously known incubators. This ensuresthat the air circulates through the chamber in which the weakly neonateis lying and provides a constant adequate supply of oxygen-rich air tothe infant.

Whilst in the incubator, the infant must be cared for, tests must oftenbe taken and the infant also needs physical contact. In the presentincubator, the problem of the incoming air drawing with it “cold”outside air into the chamber of the incubator is reduced or prevented.

The present invention will now be explained with the aid of the attachedfigures, wherein:

FIG. 1 is a sectional view through a preferred embodiment of the presentinfant incubator;

FIG. 2 is a similar sectional view through the present incubator, butwhere a porthole is open;

FIG. 3 is a sectional view through an alternative embodiment of thepresent incubator; and

FIG. 4 is a longitudinal section through a conventional incubator.

FIGS. 1, 2 and 3 show two preferred embodiments of the incubator, whilstFIG. 4 is a sectional view through a conventional incubator which issurrounded by an outer shell a and wherein an inner shell b is providedin parts of the incubator. A fan f in a lower chamber g causes the airto circulate up between the inner and the outer shell on one side anddown between the inner and the outer shell on the other side. Attendingpersonnel and parents can gain access to the infant in the incubatorthrough portholes is covered by cover c.

The present incubator, in the simplest, and preferred embodiment asshown in FIGS. 1 and 2, comprises a top section 1, 2 and a base section9, 15. The top section 1, 2 comprises an outer hemispherical shield 1 ina transparent material and an inner hemispherical shell 2 cut open atthe top, between which shells there is an air space. The outer shell 1and inner shell 2 rest on respective seats 5, 6 on the base section 9,15. The infant lies inside a chamber 23 defined by the top section 1, 2and the base section 9, 15, and preferably lies on a bottom board 10which either is soft in itself or on which a mattress is provided.

The portholes 20 in the top section 1, 2 allowing the infant to be caredfor pass through both the outer shell 1 and the inner shell 2 and areconnected by a collar 21. Additionally, the portholes 20 are normallyclosed by covers 22. The collar 21 fits closely against the portholes 20in the outer 1 and the inner 2 shell respectively.

Air is supplied to the chamber 23 through air supply pipe 11 and duct 8in the base section 9, 15, and flows out into the chamber 23 from theducts 8 between the base section 9 and the bottom board 10, up along theedges of the bottom board 10 and on the inside of the inner shell 2.This thus ensures a constant adequate flow of fresh air to the infantlying in the incubator with a minimum through-flow of air. Moreover, thebottom board 10 and the mattress, if any, will be heated from below bythe air flowing into the incubator.

When the incubator covers 22 are closed, the air flows up on the insideof the inner shell 2 and up into the top of the top section 1, 2 and isdrawn out again through the space between the outer 1 and the inner 2shell and down into an outlet duct 7 and then to the air outlet pipe 12in the base section 9, 15.

When one or more of the covers 22 are opened, the incubator is opened toits surroundings and air can flow into the chamber 23 through theportholes 20. The very fact that the air flow closest to the infant,that is, the air on the inside of the inner shell 2, is rising, largelyprevents the air closest to the infant from being mixed with cold andpossibly contaminated air. The air entering the portholes 20 isconducted upwards and away from the infant and out between the outer 1and the inner 2 shell.

To further ensure that the air flowing downwards between the shells 1, 2does not flow into the chamber 23 through the portholes in the innershell 2, a collar 21 is preferably provided which tightly connects theinner 2 and the outer 1 shell.

As shown in the figures, the base section is preferably divided into asupporting member 9 and a bottom member 15, wherein the bottom member15, which may optionally be mounted on non-illustrated wheels, containsthe equipment necessary for maintaining a flow of air which in turnmaintains the desired environment in the incubator. In the illustratedembodiment, this equipment comprises a fan 13 for the circulation ofair, and also means 14 for heating and humidifying the air. A supplyduct 18 for the supply of fresh, optionally oxygen-enriched, air to theincubator is also preferably provided in connection with the bottommember. The supply duct 18 will supply air to replace any air whichmight leak out because the incubator is not completely airtight and alsoreplace oxygen which is used by the infant in the incubator.

The supply duct 18 in the illustrated embodiment is connected to the airoutlet pipe 12 counterflow of the fan 13. The air entering through thesupply duct 18 is thus heated and humidity is introduced therein beforeit is passed into the chamber 23. The air entering the supply duct 18 ispreferably filtered, in addition to the composition of the air beingadjustable, before it is fed into the incubator.

A valve 19 is fitted at the point where the supply duct 18 enters theair outlet pipe 12. The valve 19 functions as a three-way valve which isadapted for respectively admitting and blocking the air flow through theair outlet pipe 12, whilst respectively closing and opening the supplyduct 18.

It is preferable that the valve 19 should close the air outlet pipe 12and open the supply duct 18 when one or more of the covers 22 are to beopened. The attending personnel can do this manually by manoeuvring thevalve 19 into the desired position before the door is opened and backagain after the door has been closed. It is most preferable that thevalve 19 should be manoeuvred in response to the opening of one or moreof the covers 22, for example, by means of a micro-switch in connectionwith the doors 22, or with the aid of sensors which trigger themanoeuvring of the valve 19, for example, owing to a change in pressurein the chamber 23. The incubator thus becomes a plenum chamber with asmall overpressure in the chamber 23 relative to the surroundings, andthis ensures that cold and possibly impure air is not drawn into theincubator through open portholes 20.

The bottom member 15 which contains the means for circulating, adjustingthe composition of and heating the air which is to be circulated in theincubator chamber is preferably located close to or on the floor at adistance from the chamber 23 in which the infant is to lie. The bottommember 15 houses a fan 13 as well as means 14 for heating andhumidifying the circulating air flow, thus reducing considerably theacoustic nuisance and also any electromagnetic radiation in the chamber23. The fan 13 which causes circulation of the air can never benoiseless, and for this reason sound absorbers 16, may be provided,e.g., in the air supply pipe 11 and/or in an equalising chamber 17 inthe base unit. The purpose of the equalising chamber 17, besides the.fact that the sound absorbers 16 may be placed there, is to ensure thatall the circulating air is mixed and is as homogeneous as possible.

It may be preferable that the bottom member 15 be mounted on wheels,enabling the unit to be moved easily. The bottom member 15 and thesupporting member 9 are connected to the air supply pipe 11 and the airoutlet pipe 12 which are connected to inlet duct 8 and outlet duct 7respectively in the supporting member 9.

The air supply pipe 11 and the air outlet pipe 12 may be telescopic,enabling the height of the supporting member 9 above the floor to beadjusted according to need. The pipes 11, 12 alone may form the onlyconnection between the bottom member 15 and the supporting member 9,thereby providing the necessary rigidity, but it is preferable that themembers 9, 15 should be connected by a non-illustrated supporting columnwhich provides the necessary rigidity and adjustment facility.

Whilst an infant is in the incubator, it may be preferable that theinfant be placed with a part of the body, such as the head, eitherhigher or lower than the rest of the body. In conventional incubators,this is done by building up under the mattress at the one end. This inturn will give a larger space between the mattress and the walls of theincubator which means that articles may easily be lost under themattress.

However, in the case of the present incubator, this problem can besolved by inserting a swivel in the pipes 11 and 12 and optionally alsoon the aforementioned, but non-illustrated supporting column. Thisswivel, which must be lockable at any angle of choice, is preferablylocated as high as possible in the pipes 11, 12 and the optionalsupporting column, and so as close to the supporting member 9 aspossible. For example, the swivel may coincide with the junction betweenthe pipes 11, 12 and the supporting member 9.

The bottom board 10 may be fixedly mounted on the supporting member 9.However, it is preferred that the bottom board 10 be capable of rotationto facilitate access to and care of the infant in the incubator, withouthaving to open more portholes than absolutely necessary and withouthaving to lift the infant unnecessarily. This possibility of rotatingthe bottom board 10, and thus the infant, is of great importance forbest possible access to the infant during routine nursing and care.Normally, in its simple form, the incubator will have a bottom board 10which can be rotated manually by the attending person inserting hishands into the openings and turning the bottom board 10 with his hands.If so desired, the incubator may be equipped with a locking device whichprevents the bottom board from turning unintentionally, or with a motoror the like for rotating the bottom board 10 without having to open theincubator.

FIG. 3 shows an alternative embodiment of the present incubator. Thisembodiment is preferred in cases where it is desirable that theincubator for periods of time should be capable of being used withoutthe dome-shaped outer shell 1. In principle, this incubator is like thatillustrated in FIGS. 1 and 2, and when closed, i.e., when the outershell is mounted, will be identical thereto in terms of function. Thedifference between the embodiment shown in FIGS. 1 and 2 and that shownin FIG. 3 is that the lowermost part of the inner shell 2 has been cutoff and replaced with a ring 24 which is located on the supportingmember 9 and which protects the infant against draughts from the side.When the incubator is closed, the ring 24 seals against the lower edgeof the inner shell 2.

FIG. 3 also shows the flow pattern of the air flow in the openincubator. Certain hospitals prefer to use open incubators of this kind.However, the open incubator has its limitations which are overcome bythis combination of open incubator which can readily be converted into aclosed incubator.

The present incubator is shown with a preferred dome-shaped outer shell1. A dome-shaped outer shell 1 means that there are no flat surfaces onwhich foreign bodies may be placed. Foreign bodies of various kinds willinevitably be placed on an incubator with a flat top, even though theinstructions state that this must not be done. Foreign bodies, such asitems of equipment belonging to doctors and nurses, must not be placedon the incubator top as this creates noise for the infant in theincubator, both when the items are put there and when they remain thereand vibrate on the top. It will be difficult or impossible to use thetop of the incubator as a storage space when the shell is dome-shaped.

The infant lying in the incubator will be disturbed by light. In aneonatal care unit with a plurality of incubators, there will beactivity around the clock and it will be relatively light. This willprevent the infant from having the sleep he needs. The present incubatorcan therefore be equipped with an outer shell 1 of a material whichallows control of light penetration. Such materials are known and areused inter alia in windows having adjustable light penetration and inwelding goggles where light penetration can be adjusted electronically.

The invention has been described for an incubator consisting of a bottommember 15 for each unit. However, it is also conceivable that a bottommember 15 may be connected to two or more incubator units comprising thesupporting member 9, bottom board 10 and the top section 1, 2.

What is claimed is:
 1. An incubator for premature or weakly infantscomprising a base section (9, 15) which serves as a support for both theinfant in the incubator and a protective top section (1, 2) which ismade of a substantially transparent material, wherein the base section(9, 15) houses means for the circulation of air (13) to the chamber (23)enclosed by the base section (9, 15) and the top section (1, 2), andmeans (14, 17) for adjusting the temperature, composition and humidityof the air, and also ducts (7, 12, 8, 11) for the supply of air to thechamber (23) and the outlet of air from the chamber (23) respectively,and wherein the top section consists of an outer shell (1) and an innershell (2), which shells (1, 2) rest on the base section (9, 15) andwherein the inner shell (2) is open at the top, and wherein portholes(20), preferably equipped with covers (22), are provided in the topsection (1, 2), characterised in that the ducts (8) for the supply ofair to the incubator open into the chamber (23) against and on theinside of the inner shell (2) and the ducts (7) for the outlet of airrun out between the inner (2) and the outer (1) shell.
 2. An incubatoraccording to claim 1, characterised in that the portholes (20) passthrough both the inner and the outer shell (1, 2) and that the shells(1, 2) are connected in the portholes (20).
 3. An incubator according toclaim 2, characterised in that the shells in the portholes (20) areconnected by means of collars (21) which are closely fitted in theportholes in the inner and the outer shell (1, 2) respectively.
 4. Anincubator for infants comprising a base section including: a support forthe infant in the incubator; means for circulating air; means foradjusting the temperature, composition and humidity of the air withinsaid base section being in fluid communication with said means forcirculating air; air inlet ducts in fluid communication with the meansfor adjusting the temperature, composition and humidity of the air; and,air outlet ducts in fluid communication with said means for circulationof air; a protective Top section which is made of a substantiallytransparent material, wherein the top section includes an outer shelland an inner shell positioned to form an annular chamber between theouter shell and inner shell; wherein the inner shell has an opening atthe top to provide fluid communication between the incubator chamber andthe annular chamber formed by the inner shell and outer shell; whereinthe base section and the top section are designed such that the topsection rests on the base section so as to form an incubator chamber,and wherein the air inlet ducts supply air directly to the incubatorchamber, and wherein the annular chamber formed by the inner and outershell is in fluid communication with both the incubation chamber and theoutlet ducts of the base and wherein the air directly supplied to theincubator chamber flows upwardly from air inlet ducts in the basethrough the incubation chamber to the inner shell opening at the top andis drawn out through the space between the inner and outer shells anddown into the outlet duct.
 5. The incubator of claim 4, furthercomprising one or more porthole wherein said porthole passes throughboth the inner shell and the outer shell.
 6. The incubator of claim 4,further comprising one or more porthole which is defined by a collarwhich is closely fitted to the inner and the outer shell, wherein saidporthole passes through both the inner shell and the outer shell.
 7. Theincubator of claim 4 further comprising means which allow the temporaryclosure of the outlet ducts and at the same time temporary admission ofthe supply of air from a supply duct.
 8. The incubator of claim 7,wherein the means for closure of the outlet ducts and admission of thesupply of air from the supply duct are arranged to close the outletducts and admit the supply of air from supply duct when one or more ofthe portholes are open.
 9. The incubator of claim 4, wherein the basesection includes an air treatment unit containing the means for thecirculation of air and the means for adjusting the temperature,composition and humidity of the air, and a supporting member which formsa base for the top section, wherein the air treatment unit and thesupporting member are connected to one another via pipes or tubes. 10.An incubator for premature or weakly infants comprising a base sectionincluding: a bottom board for supporting the infant in the incubator;means for circulating air, said means for circulating air having asupply side and a demand side; means for adjusting the temperature,composition and humidity of the air in fluid communication with thesupply side of said means for circulating air; one or more air inletducts in fluid communication with the means for adjusting thetemperature, composition and humidity of the air; and one or more airoutlet ducts in fluid communication with the demand side of the X meansfor circulating air; a hemispherical top section which is made of asubstantially transparent material, said hemispherical top sectionincluding an outer shell and an inner shell positioned to form an airspace between the outer shell and inner shell and wherein the topsection is designed such that the top section rests on the base sectionso as to form an incubator chamber; an opening at the top of the innershell, wherein the opening provides fluid communication between theincubator chamber and the air space formed by the inner shell and outershell and one or more porthole which is defined by a collar which isclosely fitted to the inner and the outer shell, wherein said portholepasses through both the inner shell and the outer shell and wherein saidporthole provide a means for accessing the incubation chamber withouthaving to move the top section; wherein the air inlet ducts of the basesection supply air to the incubator chamber; and wherein the airsupplied to the incubation chamber flows out the opening at the top ofthe inner shell into the air space which is in fluid communication withthe outlet ducts of the base and thus provide for the flow of air fromwithin the incubator chamber out the opening at the top of the innershell, through the air space to the outlet ducts of the base.